<html>
  <style>
    iframe {
      margin: 100px;
      height: 200px;
      width: 200px;
    }
  </style>
  <body>
    <iframe src="./click.html"></iframe>

    <script>
      function testIsolation() {
        return 'ok'
      }
      testIsolation()
    </script>
  </body>
</html>
